It is significant that upon awakening I harbored no genuine doubt of the reality of the revelation. That I had actually held conversation with a transdimensional Robert, rather than evoked the whole episode from my broodings about his disappearance and about the old illusions of the mirror, was as certain to my utmost instincts as any of the instinctive certainties commonly recognized as valid.

  The tale thus unfolded to me was of the most incredibly bizarre character. As had been clear on the morning of his disappearance, Robert was intensely fascinated by the ancient mirror. All through the hours of school, he had it in mind to come back to my living-room and examine it further. When he did arrive, after the close of the school day, it was somewhat later than two-twenty, and I was absent in town. Finding me out and knowing that I would not mind, he had come into my living-room and gone straight to the mirror; standing before it and studying the place where, as we had noted, the whorls appeared to converge.

  Then, quite suddenly, there had come to him an overpowering urge to place his hand upon this whorl-center. Almost reluctantly, against his better judgment, he had done so; and upon making the contact had felt at once the strange, almost painful suction which had perplexed him that morning. Immediately thereafter - quite without warning, but with a wrench which seemed to twist and tear every bone and muscle in his body and to bulge and press and cut at every nerve - he had been abruptly drawn through and found himself inside.

  Once through, the excruciatingly painful stress upon his entire system was suddenly released. He felt, he said, as though he had just been born - a feeling that made itself evident every time he tried to do anything; walk, stoop, turn his head, or utter speech. Everything about his body seemed a misfit.

  These sensations wore off after a long while, Robert's body becoming an organized whole rather than a number of protesting parts. Of all the forms of expression, speech remained the most difficult; doubtless because it is complicated, bringing into play a number of different organs, muscles, and tendons. Robert's feet, on the other hand, were the first members to adjust themselves to the new conditions within the glass.

  During the morning hours I rehearsed the whole reason-defying problem; correlating everything I had seen and heard, dismissing the natural scepticism of a man of sense, and scheming to devise possible plans for Robert's release from his incredible prison. As I did so a number of originally perplexing points became clear - or at least, clearer - to me.

  There was, for example, the matter of Robert's coloring. His face and hands, as I have indicated, were a kind of dull greenish dark-blue; and I may add that his familiar blue Norfolk jacket had turned to a pale lemon-yellow while his trousers remained a neutral gray as before. Reflecting on this after waking, I found the circumstance closely allied to the reversal of perspective which made Robert seem to grow larger when receding and smaller when approaching. Here, too, was a physical reversal - for every detail of his coloring in the unknown dimension was the exact reverse or complement of the corresponding color detail in normal life. In physics the typical complementary colors are blue and yellow, and red and green. These pairs are opposites, and when mixed yield gray. Robert's natural color was a pinkish-buff, the opposite of which is the greenish-blue I saw. His blue coat had become yellow, while the gray trousers remained gray. This latter point baffled me until I remembered that gray is itself a mixture of opposites. There is no opposite for gray - or rather, it is its own opposite.

  Another clarified point was that pertaining to Robert's curiously dulled and thickened speech - as well as to the general awkwardness and sense of misfit bodily parts of which he complained. This, at the outset, was a puzzle indeed; though after long thought the clue occurred to me. Here again was the same reversal which affected perspective and coloration. Anyone in the fourth dimension must necessarily be reversed in just this way - hands and feet, as well as colors and perspectives, being changed about. It would be the same with all the other dual organs, such as nostrils, ears, and eyes. Thus Robert had been talking with a reversed tongue, teeth, vocal cords, and kindred speech-apparatus; so that his difficulties in utterance were little to be wondered at.

  As the morning wore on, my sense of the stark reality and maddening urgency of the dream-disclosed situation increased rather than decreased. More and more I felt that something must be done, yet realized that I could not seek advice or aid. Such a story as mine - a conviction based upon mere dreaming - could not conceivably bring me anything but ridicule or suspicions as to my mental state. And what, indeed, could I do, aided or unaided, with as little working data as my nocturnal impressions had provided? I must, I finally recognized, have more information before I could even think of a possible plan for releasing Robert. This could come only through the receptive conditions of sleep, and it heartened me to reflect that according to every probability my telepathic contact would be resumed the moment I fell into deep slumber again.

  I accomplished sleeping that afternoon, after a midday dinner at which, through rigid self-control, I succeeded in concealing from Browne and his wife the tumultuous thoughts that crashed through my mind. Hardly had my eyes closed when a dim telepathic image began to appear; and I soon realized to my infinite excitement that it was identical with what I had seen before. If anything, it was more distinct; and when it began to speak I seemed able to grasp a greater proportion of the words.

  During this sleep I found most of the morning's deductions confirmed, though the interview was mysteriously cut off long prior to my awakening. Robert had seemed apprehensive just before communication ceased, but had already told me that in his strange fourth-dimensional prison colors and spatial relationships were indeed reversed - black being white, distance increasing apparent size, and so on.

  He had also intimated that, notwithstanding his possession of full physical form and sensations, most human vital properties seemed curiously suspended. Nutriment, for example, was quite unnecessary - a phenomenon really more singular than the omnipresent reversal of objects and attributes, since the latter was a reasonable and mathematically indicated state of things. Another significant piece of information was that the only exit from the glass to the world was the entrance-way, and that this was permanently barred and impenetrably sealed, so far as egress was concerned.

  That night I had another visitation from Robert; nor did such impressions, received at odd intervals while I slept receptively minded, cease during the entire period of his incarceration. His efforts to communicate were desperate and often pitiful; for at times the telepathic bond would weaken, while at other times fatigue, excitement, or fear of interruption would hamper and thicken his speech. I may as well narrate as a continuous whole all that Robert told me throughout the whole series of transient mental contacts - perhaps supplementing it at certain points with facts directly related after his release. The telepathic information was fragmentary and often nearly inarticulate, but I studied it over and over during the waking intervals of three intense days; classifying and cogitating with feverish diligence, since it was all that I had to go upon if the boy were to be brought back into our world.

  The fourth-dimensional region in which Robert found himself was not, as in scientific romance, an unknown and infinite realm of strange sights and fantastic denizens; but was rather a projection of certain limited parts of our own terrestrial sphere within an alien and normally inaccessible aspect or direction of space. It was a curiously fragmentary, intangible, and heterogeneous world - a series of apparently dissociated scenes merging indistinctly one into the other; their constituent details having an obviously different status from that of an object drawn into the ancient mirror as Robert had been drawn. These scenes were like dream-vistas or magic-lantern images - elusive visual impressions of which the boy was not really a part, but which formed a sort of panoramic background or ethereal environment against which or amidst which he moved.

  He could not touch any of the parts of these scenes - walls, trees, furniture, and the like - but whether thi
s was because they were truly non-material, or because they always receded at his approach, he was singularly unable to determine. Everything seemed fluid, mutable, and unreal. When he walked, it appeared to be on whatever lower surface the visible scene might have - floor, path, greensward, or such; but upon analysis he always found that the contact was an illusion. There was never any difference in the resisting force met by his feet - and by his hands when he would stoop experimentally - no matter what changes of apparent surface might be involved. He could not describe this foundation or limiting plane on which he walked as anything more definite than a virtually abstract pressure balancing his gravity. Of definite tactile distinctiveness it had none, and supplementing it there seemed to be a kind of restricted levitational force which accomplished transfers of altitude. He could never actually climb stairs, yet would gradually walk up from a lower level to a higher.

  Passage from one definite scene to another involved a sort of gliding through a region of shadow or blurred focus where the details of each scene mingled curiously. All the vistas were distinguished by the absence of transient objects, and the indefinite or ambiguous appearance of such semi-transient objects as furniture or details of vegetation. The lighting of every scene was diffuse and perplexing, and of course the scheme of reversed colors - bright red grass, yellow sky with confused black and gray cloud-forms, white tree-trunks, and green brick walls - gave to everything an air of unbelievable grotesquerie. There was an alteration of day and night, which turned out to be a reversal of the normal hours of light and darkness at whatever point on the earth the mirror might be hanging.

  This seemingly irrelevant diversity of the scenes puzzled Robert until he realized that they comprised merely such places as had been reflected for long continuous periods in the ancient glass. This also explained the odd absence of transient objects, the generally arbitrary boundaries of vision, and the fact that all exteriors were framed by the outlines of doorways or windows. The glass, it appeared, had power to store up these intangible scenes through long exposure; though it could never absorb anything corporeally, as Robert had been absorbed, except by a very different and particular process.

  But - to me at least - the most incredible aspect of the mad phenomenon was the monstrous subversion of our known laws of space involved in the relation of various illusory scenes to the actual terrestrial regions represented. I have spoken of the glass as storing up the images of these regions, but this is really an inexact definition. In truth, each of the mirror scenes formed a true and quasi-permanent fourth-dimensional projection of the corresponding mundane region; so that whenever Robert moved to a certain part of a certain scene, as he moved into the image of my room when sending his telepathic messages, he was actually in that place itself, on earth - though under spatial conditions which cut off all sensory communication, in either direction, between him and the present tri-dimensional aspect of the place.

  Theoretically speaking, a prisoner in the glass could in a few moments go anywhere on our planet - into any place, that is, which had ever been reflected in the mirror's surface. This probably applied even to places where the mirror had not hung long enough to produce a clear illusory scene; the terrestrial region being then represented by a zone of more or less formless shadow. Outside the definite scenes was a seemingly limitless waste of neutral gray shadow about which Robert could never be certain, and into which he never dared stray far lest he become hopelessly lost to the real and mirror worlds alike.

  Among the earliest particulars which Robert gave, was the fact that he was not alone in his confinement. Various others, all in antique garb, were in there with him - a corpulent middle-aged gentleman with tied queue and velvet knee-breeches who spoke English fluently though with a marked Scandinavian accent; a rather beautiful small girl with very blonde hair which appeared a glossy dark blue; two apparently mute Negroes whose features contrasted grotesquely with the pallor of their reversed-colored skins; three young men; one young woman; a very small child, almost an infant; and a lean, elderly Dane of extremely distinctive aspect and a kind of half-malign intellectuality of countenance.

  This last-named individual - Axel Holm, who wore the satin small-clothes, flared-skirted coat, and voluminous full-bottomed periwig of an age more than two centuries in the past - was notable among the little band as being the one responsible for the presence of them all. He it was who, skilled equally in the arts of magic and glass working, had long ago fashioned this strange dimensional prison in which himself, his slaves, and those whom he chose to invite or allure thither were immured unchangingly for as long as the mirror might endure.

  Holm was born early in the seventeenth century, and had followed with tremendous competence and success the trade of a glass-blower and molder in Copenhagen. His glass, especially in the form of large drawing-room mirrors, was always at a premium. But the same bold mind which had made him the first glazier of Europe also served to carry his interests and ambitions far beyond the sphere of mere material craftsmanship. He had studied the world around him, and chafed at the limitations of human knowledge and capability. Eventually he sought for dark ways to overcome those limitations, and gained more success than is good for any mortal. He had aspired to enjoy something like eternity, the mirror being his provision to secure this end. Serious study of the fourth dimension was far from beginning with Einstein in our own era; and Holm, more than erudite in all the methods of his day, knew that a bodily entrance into that hidden phase of space would prevent him from dying in the ordinary physical sense. Research showed him that the principle of reflection undoubtedly forms the chief gate to all dimensions beyond our familiar three; and chance placed in his hands a small and very ancient glass whose cryptic properties he believed he could turn to advantage. Once "inside" this mirror according to the method he had envisaged, he felt that "life" in the sense of form and consciousness would go on virtually forever, provided the mirror could be preserved indefinitely from breakage or deterioration.

  Holm made a magnificent mirror, such as would be prized and carefully preserved; and in it deftly fused the strange whorl-configured relic he had acquired. Having thus prepared his refuge and his trap, he began to plan his mode of entrance and conditions of tenancy. He would have with him both servitors and companions; and as an experimental beginning he sent before him into the glass two dependable Negro slaves brought from the West Indies. What his sensations must have been upon beholding this first concrete demonstration of his theories, only imagination can conceive.

  Undoubtedly a man of his knowledge realized that absence from the outside world, if deferred beyond the natural span of life of those within, must mean instant dissolution at the first attempt to return to that world. But, barring that misfortune or accidental breakage, those within would remain forever as they were at the time of entrance. They would never grow old, and would need neither food nor drink.

  To make his prison tolerable he sent ahead of him certain books and writing materials, a chair and table of stoutest workmanship, and a few other accessories. He knew that the images which the glass would reflect or absorb would not be tangible, but would merely extend around him like a background of dream. His own transition in 1687 was a momentous experience; and must have been attended by mixed sensations of triumph and terror. Had anything gone wrong, there were frightful possibilities of being lost in dark and inconceivable multiple dimensions.

  For over fifty years he had been unable to secure any additions to the little company of himself and slaves, but later on he had perfected his telepathic method of visualizing small sections of the outside world close to the glass, and attracting certain individuals in those areas through the mirror's strange entrance. Thus Robert, influenced into a desire to press upon the "door," had been lured within. Such visualizations depended wholly on telepathy, since no one inside the mirror could see out into the world of men.

  It was, in truth, a strange life that Holm and his company had lived inside the glass. Since the mirror had
stood for fully a century with its face to the dusty stone wall of the shed where I found it, Robert was the first being to enter this limbo after all that interval. His arrival was a gala event, for he brought news of the outside world which must have been of the most startling impressiveness to the more thoughtful of those within. He, in his turn - young though he was - felt overwhelmingly the weirdness of meeting and talking with persons who had been alive in the seventeenth and eighteenth centuries.

  The deadly monotony of life for the prisoners can only be vaguely conjectured. As mentioned, its extensive spatial variety was limited to localities which had been reflected in the mirror for long periods; and many of these had become dim and strange as tropical climates had made inroads on the surface. Certain localities were bright and beautiful, and in these the company usually gathered. But no scene could be fully satisfying; since the visible objects were all unreal and intangible, and often of perplexingly indefinite outline. When the tedious periods of darkness came, the general custom was to indulge in memories, reflections, or conversations. Each one of that strange, pathetic group had retained his or her personality unchanged and unchangeable, since becoming immune to the time effects of outside space.

  The number of inanimate objects within the glass, aside from the clothing of the prisoners, was very small; being largely limited to the accessories Holm had provided for himself. The rest did without even furniture, since sleep and fatigue had vanished along with most other vital attributes. Such inorganic things as were present, seemed as exempt from decay as the living beings. The lower forms of animal life were wholly absent.

  Robert derived most of his information from Herr Thiele, the gentleman who spoke English with a Scandinavian accent. This portly Dane had taken a fancy to him, and talked at considerable length. The others, too, had received him with courtesy and goodwill; Holm himself, seeming well-disposed, had told him about various matters including the door of the trap.